GLYNN COUNTY, Ga. -- One week after 13-month-old Antonio Santiago was shot and killed, authorities continue to release new information about that tragic day.

Two suspects, De'Marquise Elkins, 17, and his 15-year-old accomplice, were indicted on Wednesday.

Elkins' sister Sabrina, 19, was taken into custody Wednesday night.

"We know who, we know when, we know where, we know how the firearm was transported and disposed of. She was part of that," Glynn County Police Chief Matt Doering said at a media briefing Thursday.

De'Marquise's mother, Karimah Elkins, was re-arrested. Both she and Sabrina Elkins have been
charged with tampering with evidence and Karimah Elkins was also charged with
possession of a firearm by a convicted felon.

"Family members who knew what happened after the fact and chose deliberately to cover up the truth. That in itself is a tragedy."

Doering said bullet recovered from Santiago's body is now being compared at a crime lab to a .22 caliber gun discovered in a saltwater marsh located off of Highway 17, which was found 2.3 miles away from where the 13-month-old was killed.

"There is still evidence to gathered recovered, there are still witnesses to be located, and we do know they exist," Doering said.

Sabrina and Karimah Elkins remain in the Glynn County Detention Center in Brunswick.